Aircraft carrier is strong show of force by U.S.

South Koreans in a hilltop park get a view of the aircraft carrier USS George Washington in the Busan port on Saturday.

ABOARD USS GEORGE WASHINGTON — A massive nuclear-powered U.S. supercarrier began maneuvers Sunday with ally South Korea in a potent show of force that North Korea has threatened could lead to "sacred war."

The military drills, code-named "Invincible Spirit," are to run through Wednesday with about 8,000 U.S. and South Korean troops, 20 ships and submarines and 200 aircraft. The Nimitz-class USS George Washington, with several thousand sailors and dozens of fighters aboard, was deployed from Japan.

The North routinely threatens attacks whenever South Korea and the United States hold joint military drills, which Pyongyang sees as a rehearsal for an invasion. The United States keeps 28,500 troops in South Korea and 50,000 more in Japan, but says it has no intention of invading the North.

Still, the North's latest rhetoric threatening "nuclear deterrence" and "sacred war" carries extra weight following the sinking of a South Korean warship that killed 46 sailors. Seoul and Washington say a North Korean torpedo was responsible for the March sinking of the Cheonan, considered the worst military attack on the South since the 1950-53 Korean War.

The American and South Korean defense chiefs announced last week they would stage the military drills to send a clear message to North Korea to stop its "aggressive" behavior.

The exercises will be the first in a series of U.S.-South Korean maneuvers to be conducted in the Sea of Japan off Korea's east coast and in the Yellow Sea closer to China's shores in international waters. The exercises also are the first to employ the F-22 stealth fighter — which can evade air defenses — in South Korea.

South Korea was closely monitoring North Korea's military, but no unusual activity had been observed Saturday, South Korea's Yonhap news agency reported.